Mold for reinforced concrete structures



June 12, 1951 J u ow 2,556,928

MOLD FOR REINFORCED CONCRETE STRUCTURES Filed Jan. '7, 1949 H- I f 5 FIG. 2.

INVENTOR WW 5 M31617! ATTORNEYS Patented June 1?, 1951 "MOLD FOR REINFORCED CONCRETE STRUCTURES John Heywood Ludlow, Bowdon, England, assignor to Metropolitan-Vickers Electrical Company Limited, London, England, a company of Great Britain Application January 7, 1949, Serial No. 69,729 In Great Britain January 27, 1948 2 Claims. (Cl. 25-119) This invention relates to moulds for reinforced concrete structures and has particular application in moulds for reinforced concrete articles in which the reinforcing members are pre-stressed, the stressing being retained during moulding and released when the concrete has reached a sufficient degree of setting. Such a, process forms the subject of our copending patent application Serial No. 69,730, filed of even date herewith.

The main object of the present invention is to provide an improved construction of mould which is suitable for cases in which the reinforcing members are electrically heated.

According to the present invention a mould for pre-stressed concrete comprises the combination of a trough-shaped member constituting the sides and bottom, and end plates detachably secured to the trough member at each end and adapted to locate accurately the reinforcing members which pass through them together with insulation interposed in the electrical path between at least one of the end plates and the trough member and protective metal plating or the like covering said insulation.

It will be appreciated that various factors must be complied with to avoid electrically short-circuiting the reinforcing member. In the first place the wires must be fairly accurately located by the end plates to ensure that they do not move in the concrete during the setting period. Moreover it is unsuitable to make the end plates of insulating material as this is normally too fragile, and the whole moulding box must be of a robust construction as it has to withstand considerable hard usage. To this end any electrical insulation employed should be protected against mechanical damage and wear.

Preferably in carrying out the invention the insulated end is bolted to the trough, bolts passing through insulated bushings in brackets or flanges forming part of the end plates.

Both ends may be insulated but it will be appreciated that it is only actually necessary, to insulate one end from the trough.

In order that the invention may be more clearly understood reference will now be made to the accompanying drawing, in which:

Figure 1 shows a pictorial view of a trough embodying the invention, and

Fig. 2 is a. detailed sectional view showing the arrangement of the bolts.

In Fig. 1 the reference I indicates the sides of the troughmember and 2 indicates the concrete which has been poured into the trough. The trough-has flanges 3 at each end to which are secured composite end plates formed of plates 4 and 5 bolted by means of bolts 6 of which there are shown three on each side. 1 represents the reinforcing members passing through the end plates. In the particular construction shown the end plates are each formed with vertical slots 8 and side recesses 9. In assembly the plates are slid sideways so that the vertical slots in the two plates register. They are then pushed up over the reinforcing members and slid sideways into the operative position so that the reinforcing members are engaged by the edges of the two end plates and held against any sideways movement. They are then bolted to the end flanges of the trough member, the bolt holes registering in this position. This arrangement is described in the abovementioned prior patent.

Fig. 2 shows in detail the construction of one of the end flanges and cooperating end plates 4 and 5. In the arrangement of Fig. 2 the end flange is formed of a, separate angle member ID riveted to the respective side of the trough I by rivets I6. The end face of the flange thus formed is covered with insulation H and the latter is covered with a metal protecting plate l2. The back of the flange is similarly covered with insulation l I which is likewise protected with a metal plate l2.

The end plates 4 and 5 are secured by bolts [3 which pass through apertures having insulating bushings I5, and the metal plate I2 is bent through the bushing to give mechanical protection to the insulation.

The insulation I I and metal plates l2 may extend down the full length of the flange or only in the neighborhood of the bolts. In the latter case, the thickness of insulation and protective plating must be sufficient to ensure that the end plate does not contact the trough at those parts where there is no insulation. Similarly, insulation may be provided between the end of the bottom of the mould and the end plate, or a gap may be left.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A mound for reinforced concrete articles in which the reinforcing members are pre-stressed, comprising a trough shaped member constituting the sides and bottom of the mould and having flanges along its vertical edges, detachable end plates apertured to allow reinforcing members to pass therethrough, bolts securing said end plates to said flanges, insulation on the front faces of said flanges, a protective metal coating on said insulation, insulation bushings for said bolts, metal bushings protecting said insulation bushings, in-

sulation on the back faces of said flanges against which the bolts react, and a protective covering on said last mentioned insulation.

2. A mould for reinforced concrete articles in which the reinforcing members are pre-stressed, comprising a trough shaped member constituting the sides and bottom of the mould, detachable end plates for said mould, each end plate comprising two overlying plates, said plates being vertically slotted to enable them to be passed up on to the stressed reinforcing members and recessed sideways from the slots to locate the reinforcing members, flanges along the vertical edges of the trough member, bolts securing said end plates to said flanges, insulation on the front faces of said flanges to isolate the end plates, a protective metal coating on said insulation, in-

sulating bushings for said bolts, metal bushings protecting said insulating bushings, insulation on the back faces of said flanges against which the bolts react, and a protective covering for said last mentioned insulation.

JOHN HIEYWOOD LUDLOW.

REFERENCES CITED The following references are of record in the 10 file of this patent:

UNITED STATES PATENTS 

